At 4pm local time today in Moscow, Russia, the temperature surpassed 100°F for the first time in recorded history. The high temperature of 100.8°F (37.8°C) recorded at the Moscow Observatory, the official weather location for Moscow, beat Moscow's previous record of 99.5°F (37.5°C), set just three days ago, on July 26. Prior to 2010, Moscow's hottest temperature of all-time was 36.6°C (98.2°F), set in August, 1920. Records in Moscow go back to 1879. Baltschug, another official downtown Moscow weather site, hit an astonishing 102.2°F (39.0°C) today. Finland also recorded its hottest temperature in its history today, when the mercury hit 99°F (37.2°C) at Joensuu. The old (undisputed) record was 95°F (35°C) at Jvaskyla on July 9, 1914. There is little relief in sight, as the latest forecast for Moscow predicts continued highs in the 90s for most of the coming week.

A remarkable year for extreme heatFinland's new national heat record makes it the fourteenth country (or semi-independent territory) to break an all-time hottest temperature record this year. My source for extreme temperature records is Chris Burt, author of the book Extreme Weather. July in Moscow is easily going to smash the record for hottest month in Moscow's history. By my rough estimate, the temperature has been 18°F (10°C) above average this month. The record hottest July, in 1938, had temperatures 5.3°C above average. Given that the planet as a whole has seen record high temperatures the past four months in a row, it should not be a surprise to see unprecedented heat waves like the Russian heat wave. A record warm planet "loads the dice" in favor of regional heat waves more extreme than anything experienced in recorded history.

Figure 1. Russia's heat wave has contributed to a severe fire season this July. Fires on dry peat bogs east of Moscow are covering the city with smoke as this photo taken yesterday (July 28, 2010.) Tiny red dots indicate hot spots of high surface temperatures associated with fires, and multiple clusters of such dots appear east of Moscow. Dull gray smoke mixes with opaque white clouds east and northeast of the capital city. Air pollution levels in Moscow due to the smoke and smog are so high that residents have been warned to stay home rather than go in to work. Firefighters are battling 340 blazes across Russia covering 86,658 hectares (214,136 acres) amid a drought that led the government to declare weather-related emergencies in 23 crop-producing regions. Agriculture Minister Yelena Skrynnik said on July 23 that the drought had damaged 10.1 million hectares, or 32 percent of all land under cultivation, according to Bloomberg. Raging fires have destroyed hundreds of houses across Russia today and forced mass evacuations in the city of Voronezh, 300 miles southeast of Moscow, according to the Associated Press. Image credit: NASA's Aqua satellite.

Fourteen extreme national high temperature records have been set in 2010This year now ranks in second place for the most number of countries that have set extreme heat records, according to a list supplied to me today by Chris Burt. The new list removes a number of old disputed records, resulting in the year 2007 surpassing 2010 as the year with the most extreme heat records--fifteen. Keep in mind that the matter of determining extreme records is very difficult, and it is often a judgment call as to whether an old record is reliable or not. The list of countries (225) includes islands that are not independent countries, such as Puerto Rico and Greenland. One-third (33%) of those heat records were set in the past ten years. Ten years have had extreme heat records set at five or more countries on Mr. Burt's list:

I highly recommend the book Extreme Weather by Chris Burt for those interested in weather records. I thank Mr. Burt and weather record researchers Maximiliano Herrera and Howard Rainford for their assistance identifying this year's new extreme temperature records. Here's a list of the fourteen nations that have set extreme heat records this year:

Finland recorded its hottest temperature on July 29, 2010, when the mercury hit 99°F (37.2°C) at Joensuu. The old (undisputed) record was 95°F (35°C) at Jvaskyla on July 9, 1914.

Qatar had its hottest temperature in history on July 14, 2010, when the mercury hit 50.4°C (122.7°F) at Doha Airport.

Russia had its hottest temperature in history on July 11, when the mercury rose to 44.0°C (111.2°F) in Yashkul, Kalmykia Republic, in the European portion of Russia near the Kazakhstan border. The previous hottest temperature in Russia (not including the former Soviet republics) was the 43.8°C (110.8°F) reading measured at Alexander Gaj, Kalmykia Republic, on August 6, 1940. The remarkable heat in Russia this year has not been limited just to the European portion of the country--the Asian portion of Russia also recorded its hottest temperature in history this year, a 42.3°C (108.1°F) reading at Belogorsk, near the Amur River border with China. The previous record for the Asian portion of Russia was 41.7°C (107.1°F) at nearby Aksha on July 21, 2004.

Sudan recorded its hottest temperature in its history on June 25 when the mercury rose to 49.6°C (121.3°F) at Dongola. The previous record was 49.5°C (121.1°F) set in July 1987 in Aba Hamed.

Niger tied its record for hottest day in history on June 22, 2010, when the temperature reached 47.1°C (116.8°F) at Bilma. That record stood for just one day, as Bilma broke the record again on June 23, when the mercury topped out at 48.2°C (118.8°F). The previous record was 47.1°C on May 24, 1998, also at Bilma.

Saudi Arabia had its hottest temperature ever on June 22, 2010, with a reading of 52.0°C (125.6°F) in Jeddah, the second largest city in Saudi Arabia. The previous record was 51.7°C (125.1°F), at Abqaiq, date unknown. The record heat was accompanied by a sandstorm, which caused eight power plants to go offline, resulting in blackouts to several Saudi cities.

Chad had its hottest day in history on June 22, 2010, when the temperature reached 47.6°C (117.7°F) at Faya. The previous record was 47.4°C (117.3°F) at Faya on June 3 and June 9, 1961.

Kuwait recorded its hottest temperature in history on June 15 in Abdaly, according to the Kuwait Met office. The mercury hit 52.6°C (126.7°F). Kuwait's previous all-time hottest temperature was 51.9°C (125.4°F), on July 27,2007, at Abdaly. Temperatures reached 51°C (123.8°F) in the capital of Kuwait City on June 15, 2010.

Iraq had its hottest day in history on June 14, 2010, when the mercury hit 52.0°C (125.6°F) in Basra. Iraq's previous record was 51.7°C (125.1°F) set August 8, 1937, in Ash Shu'aybah.

Pakistan had its hottest temperature in history on May 26, when the mercury hit an astonishing 53.5°C (128.3°F) at the town of MohenjuDaro, according to the Pakistani Meteorological Department. While this temperature reading must be reviewed by the World Meteorological Organization (WMO) for authenticity, not only is the 128.3°F reading the hottest temperature ever recorded in Pakistan, it is the hottest reliably measured temperature ever recorded on the continent of Asia.

Myanmar (Burma) had its hottest temperature in its recorded history on May 12, when the mercury hit 47°C (116.6°F) in Myinmu, according to the Myanmar Department of Meteorology and Hydrology. Myanmar's previous hottest temperature was 45.8°C (114.4°F) at Minbu, Magwe division on May 9, 1998. According to Chris Burt, author of the authoritative weather records book Extreme Weather, the 47°C measured this year is the hottest temperature in Southeast Asia history.

Ascention Island (St. Helena, a U.K. Territory) had its hottest temperature in history on March 25, 2010, when the mercury hit 34.9°C (94.8°C) at Georgetown. The previous record was 34.0°C (93.2°F) at Georgetown in April 2003, exact day unknown.

The Solomon Islands had their hottest temperature in history on February 1, 2010, when the mercury hit 36.1°C (97°F) at Lata Nendo (Ndeni). The previous record for Solomon Islands was 35.6°C (96.0°F) at Honaiara, date unknown.

Columbia had its hottest temperature in history on January 24, 2010, when Puerto Salgar hit 42.3°C (108°F). The previous record was 42.0°C (107.6°F) at El Salto in March 1988 (exact day unknown).

90L forms in far eastern AtlanticNHC has designated an area of thunderstorms in the tropical Atlantic as Invest 90L (8.5 N, 30.0 W). Microwave remote sensing suggests there are some decent thunderstorms in 90L, as peak rain rates were around 1 - 2 inches per hour. According to CIMMS wind-shear analyses, 90L is under a moderate 10 - 15 knots of wind shear, and upper level winds over the disturbance are diverging, which creates a vacuum effect that will enhance updrafts and thunderstorm growth. The disturbance is tracking into a broad area of weak shear to the west and northwest. The steering currents for 90L are to the west-northwest, which will move it into this area of weaker shear. The disturbance is at 8°N latitude, which is too close to the Equator to leverage the Earth's spin very well to spin up. As 90L's west-northwest motion carries it farther from the Equator, the additional spin the disturbance gains from the Earth's rotation will aid development, particularly once 90L gets north of 10°N latitude.The Saharan Air Layer with its dust and dry air lurks just to the north of 90L, but the SHIPS model predicts 90L will remain far enough from the dry air over the next five days so that it will not interfere with development.

Figure 2. IR Satellite Composite of 90L taken at 5:40 pm EDT.

Figure 3. Saharan Air Layer analysis courtesy of the University of Wisconsin CIMSS group.

Model Forecasts and ClimatologyThe latest 2pm EDT (18Z) runs of the GFDL and HWRF models show 90L developing into a hurricane 3 - 5 days from now. These models suggest that 90L will pass well northeast of the Lesser Antilles Islands. The 18Z GFS model develops 90L into a tropical storm about 7 days from now, and forecasts a track through the northern Lesser Antilles Islands 7 - 8 days from now. The 18Z NOGAPS and 12Z ECMWF models show little development of 90L. The GFDL and HWRF models are too aggressive developing 90L, and likely show too much of a northward motion due to excessive depth of the system they portray. The GFS solution, showing a more delayed development and possible threat to the Lesser Antilles Islands is probably more reasonable. Looking at climatology based on research done by Dr. Bob Hart at Florida State University,, 90L has a 36% chance of developing into a tropical cyclone by 2pm Saturday. NHC is putting these odds at 20%. Dr. Hart also has an experimental product showing that historically, about 30% of all tropical cyclones at 90L's current position eventually hit land as a hurricane. Of course, 90L is not yet a tropical cyclone, but these odds suggest that 90L has the potential to become a dangerous Cape Verdes-type hurricane that will affect land.

Next updateI'll have an update by 8pm Friday.

Jeff Masters (with lots of help from Rob Carver on the 90L portion of the post!)

Very true, it begs the question, what's up with all of them this year. I'm like, seriously! Even the ECM has been out of it, this year, thus far. It's best to just go by real-time action, Ike, you know what I mean?

I know exactly what you mean. Anything beyond 72-96 hours is like throwing darts at a dart board.

NICE LOOKING WAVE EXITED THE AFRICAN COAST THIS MORNING AND MODELGUIDANCE IS STARTING TO SHOW SOME CONSENSUS THAT WE`LL SEE ATROPICAL CYCLONE IN THE ATLC BASIN IN AROUND FIVE DAYS FROM NOW.CLIMATOLOGY SUGGEST THAT A WAVE ALONG 23W WILL TAKE AT LEAST SIXDAYS TO TRAVERSE THE ENTIRE TROPICAL ATLC.

NICE LOOKING WAVE EXITED THE AFRICAN COAST THIS MORNING AND MODELGUIDANCE IS STARTING TO SHOW SOME CONSENSUS THAT WE`LL SEE ATROPICAL CYCLONE IN THE ATLC BASIN IN AROUND FIVE DAYS FROM NOW.CLIMATOLOGY SUGGEST THAT A WAVE ALONG 23W WILL TAKE AT LEAST SIXDAYS TO TRAVERSE THE ENTIRE TROPICAL ATLC.

Just a thank you from a lurker (whose 8 year old's dream job is a meteorologist) for the acronym dictionary at the beginning of each of your synopses. That thing is a life saver for following along here! And your analyses are excellent. Thanks again!

Quoting CybrTeddy:IMO they're going to have to relocate 90L (or deactivate it and put 91L) On to the wave emerging off Africa because its sucking the life out of 90L and looks pretty impressive. 90L will supply this with a LLC, so things will get going once they merge.

Quoting Bipartisanship:Ike, a word to the wise, try not to take it too literal, unless this afternoon's version of the ECM decides to show the same thing, ALRIGHT? If it does, then it'll be game, set, match for 90l. I'm not buying into anything that defective GFS shows for now.

I hear ya. I know it's got issues. Tell you the truth...I don't trust any model enough to bet my paycheck on what it shows.

Actions speaks louder than words. I don't believe anything until I see it in 2010. I've been bitten too many times.

If everything the NOGAPS has shown in 2010 were true, we would be up to the G or H storm by now.

If everything the CMC has shown in 2010 were true, we would be in the Greek letters by now.

Quoting ho77yw00d:IMO the whole picture thing was blown out of proportion, I didnt mean to insult anyone and I was only wondering what they meant.. Thats all! I didnt think anyone was rude though but thats just my opinion! BACK TO WEATHER.....

IMO the whole picture thing was blown out of proportion, I didnt mean to insult anyone and I was only wondering what they meant.. Thats all! I didnt think anyone was rude though but thats just my opinion! BACK TO WEATHER.....

Very potent wave off of Africa, and Hurricanes101 is right. This is what the models were showing, remember how people on here were saying they were developing the wave and not the disturbance which turned out to be a wave afterall? Once these emerge, expect slow to gradual development, if any. I don't see how this can become a fish storm, the high is too strong and a ridge is building west of the high, do to the MJO that Levi pointed out on his video, great video as always.